Pandemic (H1N1) 2009 cases, Buenos Aires, Argentina.

To determine clinical and virologic characteristics of pandemic (H1N1) 2009 in Buenos Aires, Argentina, we conducted real-time reverse transcription–PCR on samples from patients with influenza-like illness, June 11–30, 2009. Of 513 patients tested, 54% were positive for influenza virus subtype H1N1. Infection rate was lowest for patients ≥60 years of age.